Iris de Nie

TABLE OF CONTENTS Chapter 1 General introduction and thesis outline 7 Chapter 2 Reflecting on the importance of family building and fertility preservation: transgender people’s experiences with starting gender-affirming treatment as adolescent 19 Chapter 3 Impaired semen quality in trans women: prevalence and determinants 35 Chapter 4 A cohort study on factors impairing semen quality in transgender women 51 Chapter 5 Successful restoration of spermatogenesis following gender-affirming hormone therapy in transgender women 67 Chapter 6 Histological study on the influence of puberty suppression and hormonal treatment on developing germ cells in transgender women 81 Chapter 7 Incidence of testicular cancer in trans women using gender- affirming hormonal treatment: a nationwide cohort study 109 Chapter 8 Prostate cancer incidence under androgen deprivation: nationwide cohort study in trans women receiving hormone treatment 121 Chapter 9 General discussion and future perspectives 133 Appendices References 144 List of abbreviations 152 Author affiliations 154 Summary in Dutch – Nederlandse samenvatting 158 Portfolio 164 About the author 168 Acknowledgements – Dankwoord 170